Notion after years of trello.
Once you get how it works and how to use it your way it just blows everything else out of the window.
I have sql like relations through notes,topics,websites,people and much more. My setup: https://i.imgur.com/Cd22G8x.png
I used Notion for about six months, including paying for the service. I could never get the hang of it. I wrote to the company and said: "Give me an overview explanation of how it all fits together so that I can distinguish pages from templates, etc."
But instead all they could point me to was endless reference pages on one feature or another. So, I was never able to get the hang of it, which as you say, is necessary to put it to best use. After several months, I cancelled my subscription and told them they need better docs: an overview/getting started guide, rather than a series of man pages.
